Antenna phase pattern measurements at millimeter wave frequencies using the differential phase method with only one power meter

The differential phase measurement method has been improved to need the use of only one power meter instead of three power meters. This enables accurate antenna phase pattern measurements with a simplified set-up, accompanied by the reduction in cost. All advantages of the differential phase measurement method are still also available, e.g. there is no need to phase lock oscillators or to use rotary joints. The measurement results for an antenna at 110 GHz are presented. A good agreement with earlier data was obtained.     

Infinite factorization of multiple non-parametric views

Combined analysis of multiple data sources has increasing application interest, in particular for distinguishing shared and source-specific aspects. We extend this rationale to the generative and non-parametric clustering setting by introducing a novel non-parametric hierarchical mixture model. The lower level of the model describes each source with a flexible non-parametric mixture, and the top level combines these to describe commonalities of the sources. The lower-level clusters arise from hierarchical Dirichlet Processes, inducing an infinite-dimensional contingency table between the sources. The commonalities between the sources are modeled by an infinite component model of the contingency table, interpretable as non-negative factorization of infinite matrices, or as a prior for infinite contingency tables. With Gaussian mixture components plugged in for continuous measurements, the model is applied to two views of genes, mRNA expression and abundance of the produced proteins, to expose groups of genes that are co-regulated in either or both of the views. We discover complex relationships between the marginals (that are multimodal in both marginals) that would remain undetected by simpler models. Cluster analysis of co-expression is a standard method of screening for co-regulation, and the two-view analysis extends the approach to distinguishing between pre- and post-translational regulation.     

On the state complexity of reversals of regular languages

We compare the number of states between minimal deterministic finite automata accepting a regular language and its reversal (mirror image). In the worst case the state complexity of the reversal is 2ⁿ for an n-state language. We present several classes of languages where this maximal blow-up is actually achieved and study the conditions for it. In the case of finite languages the maximal blow-up is not possible but still a surprising variety of different growth types can be exhibited.     

Genes without prominence: a reappraisal of the foundations of biology

The sequencing of the human genome raises two intriguing questions: why has the prediction of the inheritance of common diseases from the presence of abnormal alleles proved so unrewarding in most cases and how can some 25 000 genes generate such a rich complexity evident in the human phenotype? It is proposed that light can be shed on these questions by viewing evolution and organisms as natural processes contingent on the second law of thermodynamics, equivalent to the principle of least action in its original form. Consequently, natural selection acts on variation in any mechanism that consumes energy from the environment rather than on genetic variation. According to this tenet cellular phenotype, represented by a minimum free energy attractor state comprising active gene products, has a causal role in giving rise, by a self-similar process of cell-to-cell interaction, to morphology and functionality in organisms, which, in turn, by a self-similar process entailing Darwin''s proportional numbers are influencing their ecosystems. Thus, genes are merely a means of specifying polypeptides: those that serve free energy consumption in a given surroundings contribute to cellular phenotype as determined by the phenotype. In such natural processes, everything depends on everything else, and phenotypes are emergent properties of their systems.     

An experimental investigation into the pre-treatment of synthetic membranes using sodium hydroxide solutions

In this paper the effect of two pre-treatment methods are compared experimentally for the filtration of (i) a spent sulphite liquor (17.8 wt.% dry solids) using a 20 kg mol⁻¹ molar mass cut off (MMCO) fluoropolymer membrane and (ii) a molasses solution (45° Brix) using a polysulphone (Psf) membrane (1.5 μm pore size). Both feeds are industrially relevant, and subject to severe fouling issues when membranes are used in their subsequent processing. The pre-treatment methods evaluated were: (i) conditioning with water at 60 °C only [Protocol 1], and (ii) conditioning with water at 60 °C followed by cleaning with 0.5 wt.% NaOH [Protocol 2]. Results are presented that confirm the benefits of sodium hydroxide preconditioning upon performance, supporting the suggestion by some membrane manufacturers that this step be included as part of the pre-treatment protocol.     

Development of color density concept with color difference formulas in respect to human vision system

The aims of this study are to develop the color density concept and to propose the color density based color difference formulas. The color density is defined using the metric coefficients that are based on the discrimination ellipses and the locations of the colors in the color space. The ellipse sets are the MacAdam ellipses in the CIE 1931 xy-chromaticity diagram and the chromaticity-discrimination ellipses in the CIELAB space. The latter set was originally used to develop the CIEDE2000 color difference formula. The color difference can be calculated from the color density for the two colors under consideration. As a result, the color density represents the perceived color difference more accurately, and it could be used to characterize a color by a quantity attribute matching better to the perceived color difference from this color. Resulting from this, the color density concept provides simply a correction term for the estimation of the color differences. In the experiments, the line element formula and the CIEDE2000 color difference formula performed better than the color density based difference measures. The reason behind this is in the current modeling of the color density concept. The discrimination ellipses are typically described with three-dimensional data consisting of two axes, the major and the minor, and the inclination angle. The proposed color density is only a one-dimensional corrector for color differences; thus, it cannot capture all the details of the ellipse information. Still, the color density gives clearly more correct estimations to perceived color differences than Euclidean distances using directly the coordinates of the color space.     

The effect of temperature on the pulsed current processing behaviour and structural characteristics of porous ZSM-5 and zeolite Y monoliths

Hierachically porous monoliths of ZSM-5 and Y zeolites have been prepared by pulsed current processing (PCP). The densification behaviour and structural characteristics during rapid thermal treatment of the zeolites have been determined and related to the influence of the Si:Al ratio on the thermal stability of the zeolites. Monoliths of macroscopic shape can be prepared with an insignificant loss of surface area and micropore volume when the PCP-treatment was performed at temperatures below a critical maximum PCP temperature (T_PCP). Full-profile fittings of the powder X-ray diffraction patterns showed that the lattice strain of zeolite Y increases rapidly above the critical T_PCP while the ZSM-5 zeolites undergo a phase transition from orthorhombic to monoclinic. The use of a novel ceramic processing route for the production of the zeolite monoliths that do not significantly influence the structural characteristics and surface area of the starting materials has a potential to be of importance in catalysis and gas separation applications.     

Sandwiches and milk with varying fat and sodium contents: What is the best combination?

Saltiness and fattiness were systematically varied in combinations of wheat bread (unsalted vs regular-salt), spread (none vs regular-salt and regular-fat), cheese (low-salt and low-fat vs low-fat). All possible combinations, amounting to sixteen samples of sandwich and milk, were presented to 43 subjects for ratings of pleasantness. The subjects also rated the pleasantness of individual components. The unsalted bread without spread but with low-salt, low-fat cheese and any of the milk types received the lowest hedonic ratings, whereas the regular-salt bread with spread and with any of the cheese and milk options received the highest. The pleasantness of individual components predicted the pleasantness of a combination by only 10–40% (multiple regression analysis). Thus the pleasantness of an entity depended on the pleasantness of components only to a very limited extent. The absence of major elements, such as spread on bread or the salty taste in bread, had major effects on acceptance.